1. Field
An aspect of the embodiments discussed herein is directed to a method of manufacturing a semiconductor device and a semiconductor device related to hydrophobic treatment of the semiconductor device.
2. Description of the Related Art
In recent years, in order to improve element characteristics of a ferroelectric memory (ferroelectric random access memory (FRAM)) in which information is retained in ferroelectric film capacitors using ferroelectric polarization inversion, development has been pursued. The ferroelectric memory is a non-volatile memory in which information stored therein is not lost even when a power supply is removed. In the ferroelectric memory, capacitors each having two electrodes and a ferroelectric film interposed therebetween are provided. As a material for the ferroelectric film forming the capacitor of the ferroelectric memory, for example, a ferroelectric oxide having a perovskite structure, such as lead titanate zirconate (Pb(Zr, Ti)O3, hereinafter referred to as “PZT”), has been primarily used.
Inspection is performed a plurality of times for one ferroelectric memory, and only ferroelectric memories finally recognized as good products are packed for shipment. Hence, the ferroelectric memory as described above has pad electrodes to be brought into contact with a measurement terminal for inspection or to be connected to an external circuit on the same layer as the topmost wiring layer or a layer thereabove. Since the pad electrode is a connection portion to be brought into contact with a measurement terminal or to be connected to an external circuit, the upper surface of the pad electrode must be exposed.
When the inspection as described above is performed, a front end of a measurement terminal of a tester is brought into contact with the pad electrode; however, for example, when the number of inspections is large as in the case of a memory incorporating logic LSI, a hard measurement terminal is repeatedly brought into contact with the same pad.
When being brought into contact with the pad electrode as discussed above, the measurement terminal may break a metal film forming the surface of the pad electrode and a barrier metal provided thereunder, and a wire disposed under the pad electrode may be exposed in some cases. That is, the metal film is broken and curled up, and the wire provided thereunder is exposed. When wire bonding is performed in an assembly operation on the pad electrode in the state discussed above, the adhesion of a bonding wire is degraded.
A semiconductor device and a manufacturing method thereof have been discussed, for example, in Japanese Laid-open Patent Publication No. 2004-296643, in which after a curled-up metal film forming a surface of a pad electrode is selectively removed, a wire bonding operation is performed.
According to the configuration discussed in Japanese Laid-open Patent Publication No. 2004-296643, the adhesion of a bonding wire may be improved. However, in the semiconductor device having a ferroelectric film as discussed above, when moisture enters the pad electrode through the surface thereof, it may probably reach a wire, a transistor, and a capacitor having a ferroelectric film through interlayer insulating films in some cases. When moisture reaches the capacitor having a ferroelectric film, particularly, characteristics of the ferroelectric film are degraded. The reason for this is believed that due to hydrogen derived from the moisture that entered as discussed above, the ferroelectric film is reduced, oxygen defects occur thereby, and the crystallinity is degraded. As a result, degradation of characteristics, such as the remanent polarization and the dielectric constant, occur. In addition, when hydrogen enters, the characteristics of the capacitor having a ferroelectric film is more directly degraded as compared to the case of moisture.